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Thursday, July 29, 2010

Conquering Cis-Lunar Space with Shuttle and ULA Derived Technologies

by Marcel F. Williams

Congress has now made it clear that they want the immediate development of a heavy lift vehicle and a crew exploratory vehicle capable of beyond LEO missions and as a back up transport to the ISS. They have also made it clear that they want NASA to utilize technologies derived from both the Space Shuttle and Ares I/V programs since billions of tax payer money has already been invested in these technologies.

Some, however, have argued that utilizing a heavy lift vehicle as a crew transport to LEO violates the philosophy of improving safety by not combining crew transport with cargo transport. This was part of the driving philosophy of former NASA director, Griffin, when he decided to advocate the development of the Ares I as an ultra-safe crew transport vehicle and the Ares V as a mega-heavy lift cargo vehicle.

Recently, NASA has been promoting a philosophy of developing new transport systems that can be utilized not only by NASA but also potentially by the military space program and by private commercial space programs. The advantage of such a philosophy is that increased demand for common transport systems or components could reduce cost for everyone that utilizes such vehicles or components.

The deployment of space depots has been argued as another means for reducing the cost of space travel beyond LEO. And the development of reusable space craft that utilize in situ resources on the Moon or the asteroids has also been proposed as a way to reduce the cost of space travel.

But is there a way that NASA could cheaply incorporate all of these ideas? I believe the answer is yes!The first step is to develop a simple shuttle derived core vehicle similar to that proposed by Boeing. The Boeing shuttle derived core vehicle could be utilized to transport humans into orbit without using solid rocket boosters (SRBs). But with SRBs, the Boeing core vehicle could be used as a heavy lift vehicle.

Boeing also proposed using a stretched hypergolic fueled SM (Service Module), requiring an extra 8 to 9 metric tons of fuel in order for the crew launch vehicle to transport a 20 metric ton capsule and crew to LEO. The United Launch Alliance (ULA), however, has proposed using an ACES 41 as a LOX/LH2 fueled Service Module. Utilizing an ACES 41 SM with a shuttle derived crew launch booster which I'll call the SD-CV (shuttle derived core vehicle) could potentially lift more than 30 metric tons to LEO. Since the ULA plans to use the ACES 41 as a common upper stage for both the Atlas and the Delta IV, the high production demand for the ACES 41 by NASA and the ULA should help to reduce cost for the ACES 41.

SD-CV (Shuttle Derived Core Vehicle) and ULA's ACES 41 (credit ULA) concept used as a Service Module for an Orion capsule.

Boeing's heavy lift vehicle concept with an EDS could lift up to 120 metric tons to LEO while the crew vehicle could lift more than 30 metric tons to LEO (150 metric tons in combination). That's enough capacity to launch nearly 60 metric tons of payload to trans lunar injection or to the Earth-Lunar L1 Lagrange point.

The SD-HLV with an Altair lunar landing vehicle and the SD-CV with a Command Module (CM) and an ACES 41 Service Module (SM).

An SD-CV crew vehicle with the ability to launch over 30 metric tons into orbit would also give it approximately the same capabilities as the current space shuttle with the exception of not being able to return large payloads back to Earth. But the SD-CV should be substantially cheaper to operate than the shuttle since it does not require SRBs. The SD-CV could also be one of the safest manned launch vehicles ever developed since it would only have two stages, with each stage having multiple engines capable of supplementing a failed engine in both stages. Being hydrogen fueled would also make it potentially the greenest manned space vehicle ever developed. While a manned launched SD-HLV would still be safer than a space shuttle launch, the SD-CV should be equally as safe as a man rated Atlas V-401 and a substantially safer vehicle than an SD-HLV, Delta IV heavy, or a Falcon 9 (the two stage Falcon 9 only has one engine for the upper stage so a single engine failure in the upper stage would terminate the mission).

Any space capsule chosen by NASA for the Orion CEV (Crew Exploratory Vehicle) should be able to be used by NASA and private industry on top of an ACES 41 which could be used by an Atlas V or a Delta IV heavy. Again, the higher the demand for a particular crew capsule, the lower the capsule's production cost will be.

An SD-HLV lunar mission would launch an Altair into Earth orbit for a rendezvous with a CM-SM-ACES 41, or it could use the Altair to transport unmanned payloads (lunar base modules, vehicles, oxygen factories, etc.) weighing more than 10 metric tons to the lunar surface.

Because of its large payload capacity, some might question the private commercial viability of the SD-CV as a crew launcher against much smaller potentially manned rated launch vehicles like the Atlas 5 and the Falcon 9. However, if a payload carrier is placed between the command module and the service module, the shuttle derived crew carrier could also transport and additional 20 metric tons of cargo to LEO. While the space shuttle is banned from carrying commercial loads into orbit, a private commercial company would have no such restrictions!

SD-CV could be launched into to orbit for a rendezvous with the Altair for a lunar mission or it could be used to transports crew and cargo to the ISS or to private commercial space stations.

There are two principal options for the EDS (Earth Departure Stage) for the unmanned heavy lift vehicle: one that uses a single JX-2 engine and one that uses multiple RL 10 engines. Since the ACES 41 in this concept and the Altair lunar lander would also use RL-10 engines, using RL-10s in the EDS, Service Module, and Altair lunar lander would obviously increase the demand for the RL-10 which should reduce the production cost for the engine.

After the Orion-CM-SM-ACES 41 docks with the Altair and EDS (Earth Departure Stage), the EDS provides most of the delta-v for transferring the Altair and the Orion to the L1 Lagrange point.The SM-ACES 41 provides the rest of the delta-v requirements for reaching L1 in addition to the delta-v for returning passengers to Earth. Limiting the Orion CM-SM-ACES 41 to L1 would substantially reduce the delta-v requirements for a lunar mission. The single stage Altar vehicle would transport up to three metric tonnes of payload (crew transport module, cargo, and crew) from L1 to the lunar surface and back to L1. L1 departure for the Altair vehicle enhances the ability of the lunar lander to conveniently land at practically any point on the lunar surface.

The Altair lunar landing vehicle was originally proposed to have a LOX/LH2 descent stage and a hypergolic fueled ascent stage. However, there is no reason why a lunar landing vehicle can't be a single stage vehicle by simply using the descent stage to land and lift a small crew module weighing about 3 metric tons with four passengers and payload. This would mean that NASA would only have to develop one lunar vehicle instead of two, substantially reducing development cost. Plus the Altair descent stage would use an RL-10 engine which would further reduce the cost of the RL-10 engine used by both NASA and the ULA.

A single stage Altair vehicle with a crew transport module would be much cheaper to develop than the two stage Altair concept that uses both a LOX/LH2 descent stage and a hypergolic fueled ascent stage. For long term missions to a lunar base facility, a simple light weight aluminum sun shade could be used to cover and shield the vehicle from direct sunlight on the lunar surface in order to reduce hydrogen and oxygen fuel boil-off.

Any Moon base program that involves the production of oxygen and even hydrogen from lunar resources would have a dramatic effect on reducing the cost of space travel within cis-lunar space. Without the need for a vehicle to carry oxygen and hydrogen fuel to the lunar surface for its eventual return to orbit, manned missions to a lunar base could carry several metric tons of additional cargo plus additional passengers to the lunar surface instead of just a few hundred kilograms with crew as currently envisioned by the Constellation program. Lunar oxygen and hydrogen could also allow an Altair to be used as a reusable manned vehicle operating from the lunar surface to lunar orbit or from the lunar surface to L1.

A reusable single stage Altair crew transport vehicle could be fueled with oxygen and hydrogen from an L1 space depot for transporting passenger to the Moon and with in situ oxygen and hydrogen from the lunar surface for returning passengers to L1 requiring a much smaller vehicle that simply uses shorter cryogenic 0xygen and hydrogen fuel tanks.

A stretched Altair vehicle, using longer hydrogen and oxygen fuel tanks, combined with an ACES 41 tanker could be used to supply an L1 depot with oxygen and hydrogen produced on the lunar surface. Such a tanker could also be used to supply lunar bases not located near the poles with hydrogen.

So some day a paying tourist or a lunar lotto winner aboard a Falcon 9, Atlas V, Delta IV heavy, or a SD-CV could simply fly into orbit and dock with another ACES 41 (originally fueled with lunar oxygen and hydrogen at an L1 space depot) to travel to L1. At the Lagrange point, passengers would dock with an L1 fueled reusable Altair vehicle which would transport them to the Moon where they could perhaps stay at an appropriately mass shielded a Bigelow lunar hotel. The same lunar vehicle could be refueled with lunar oxygen and hydrogen for the tourist's return to L1 where they would dock with a CM-SM-ACES 41 equipped with an aerobreaking hypercone that would take them back to Earth orbit. There they would dock with a space capsule or Dreamchaser space plane that would finally return them to the Earth. That might be a very interesting vacation perhaps 15 or 20 years from now!

16 comments:

There has been much oversimplification, bordering on wilful obtuseness, about the issue of not combining crew transport with cargo transport. Even a simple review of the intent of this recommendation makes it clear that a launcher carrying crew in a separate vehicle from cargo, thus allowing rapid crew escape from launch problems, would address this safety concern. Griffin was particularly guilty of refusing to back down from his mistaken understanding of this aspect of the Shuttle's safety lessons.

I think that the safety issues involving the space shuttle are hugely overstated. An LAS would certainly enhance the crew safety of practically any liquid fueled vehicle. However, there have been some questions as to whether or not an LAS could escape a solid rocket motor explosion.

But there could still be severe economic consequences for NASA or a private space company if they actually had to use an LAS during a flight. So I think the philosophy of maximizing crew safety by reducing the complexity of a crew launch vehicle as much as possible is a good idea.

The biggest flaw with the shuttle as a cargo vehicle, IMO, is that it always had to be manned.

Mr. Williams,Once again I feel this is the only correct path to follow. This could be well exacuted with the Senate version of the NASA Bill. It has all the needed ingredients to make major incredimental "baby steps" needed to achieve BEO and LEO and beyond manned space flight. Everything is all ready in place! Please read post on vote between, by the people, on Congressional House and The Senate.

Gaetanomarano - Every time I read an article about NASA HLV, ARES I & V, Jupiter Direct or even Side Mount Heavy. All I see is comments from this guy Gaetanomarano. His words and wrighting are over spaced in an unreadable content. He alway's states this was my original idea or it would be done better MY WAY! I feel his best efforts towards the human race would be to provide a better way to design & put the plastic end's on shoe laces. Sorry, being humble and silent is better. In his case, once again I'm sorry, I couldn't !!

Its funny really that after all of the comments and the seeming mutany of the silent word of seething NASA operatives being represented in what is wholely an illeagal dispute with little substance of equity supporting it for the long term, the continuing proposals for heavy lifting vehicles and cargo vehicles whether combined with human rated [passenger] or singular programme to low earth orbit and beyond, I still think that the shuttle programme is in its infancy.

I forsee similar shuttle 'paths' being utilised for training and for civilian operations for low earth orbit simply because of its reliability, the problem is that most of NASA's whizz kid engineers want to build their own rockets and different variations of engine that have actually seen reasonable success for potential deep space.

If we're honest, I don't beleive any of the proposed vehicles will be suitable for deep space, I think President Barack Obama knows that, and justifiably would not spend another 50-100 billion dollars sending 30 astronaughts to a place that really has no value to us as an outpost for an operation that is completely unjustified for its returns.

I think the vehicle that we all want for heavy lifting is as we all know not a rocket, and for that I think that when the issue has been resolved for deep space, I think the shuttle will be used again as its workforce is trained for the scenario, I see the shuttle being slightly modified with more thrust, but, maintaining shape and payload???

Traveling several months through interplanetary space is going to require several hundred metric tons of mass shielding to protect the human brain from the deleterious effects of heavy nuclei. Then you have to add the weight of the spacecraft and the fuel required to move such a heavy vehicle through interplanetary space.

No heavy lift vehicle addresses this problem. Light sails are the only solution, IMO.

I feel we all agree that the safety issue is not one. Sorry for changing the blog! But, I would like to see some more input on the safety and design of Bimodial Nuclear Reactors for electrical generation and NTR's. We have NERVA/ROVER Solid core using a pebble bed reactor. Gas core in idea's and a Thorium Liquid type reactor being dicussed alot these day's. Especially with in The US Navy along with the Pollywell design. They both have had some pork monies rolled their way's. All in all, my thought's for interstellar travel would be best suited with a (if possible)BimodialFragmented Fission Dusty Thorium NTR to explore and habitate. The Boeing/Bigelow team could make this happen as long as funding was giving to the advancment of Nuclear Science. In our life times!

In a personal commmunication between steven Rappolee and Bernard Kutter of ULA we kicck around the idea of using a fuel depot system with storage and transport of liqued heluim for space telescope servicing missions.

"The knowledge that we have now is but a fraction of the knowledge we must get, whether for peaceful use or for national defense. We must depend on intensive research to acquire the further knowledge we need ... These are truths that every scientist knows. They are truths that the American people need to understand." (Harry S. Truman 1948).